Electric controller.



PATENTED JULY 4, 1905.

G. S. RENO.

ELECTRIC CONTROLLER.

' APPLICATION FILED MAB-11.1906.

requires only occasional inspection.

UNITED. STATES Patented July 4, 1905.

PATENT OFFICE.

ELECTRIC CONTROLLER.

SPECIFICATION forming part of Letters Patent No. 793,848, dated July 4, 1905.

Application filed March 11 1905. Serial No. 249,576.

To all whom, it may concern.-

Be it known thatI, CHARLES S. RENO, a citizen of the United States, residing at (lovington, in the county of Kenton and State of Kentucky, have invented certain new and useful Improvements in Electric Controllers, of which the following is a full, clear, and exact specification.

My invention relates to electric controllers, and although particularly adapted for the control of electric motors in connection with the operation of elevators it is generally applicable to motors which are frequently started and stopped or reversed.

By my invention a controller is constructed which is simple in construction and operation,v

very compact, all parts easily accessible, and

Moreover, the first cost is low and the cost for repairs is reduced to a minimum.

These and other objects are attained by my invention. as will more fully appear from the following description, taken in connection with the accompanying drawings.

Figure 1 is a perspective view of one form of my improved controller assembled. Fig. 2 is a vertical sectional view of certain parts through the axis of the main switch. Fig. 3 is a perspective view of the two-part operating-cam. Fig. 4 is a development of the same. Fig. 5 is a diagram of the main connections, and Fig. 6 is an enlarged detail view.

Generally my invention contemplates the use of a series resistance in the armature-circuit of the motor which reduces the startingcurrent and which may, if desired, be used to control the speed of the motor. I prefer to keep the field of the motor constantly excited during its operation and to reverse the direction of rotation by reversing the armaturecurrent. I also provide means for weakening the field strength to obtain increased speeds after the armature resistance is cut out and have all parts definitely under control of a single operating means.

Referring to Fig. 1, there is indicated a frame 1 of substantially rectangular form, having within the same resistance-coils 2 for starting and regulating the speed of the motor. At 3 are indicated the armature-resistance contacts, over which the insulated outer end of arm 4 passes for varying the amount of resistance in the armature-circuit. The resistance-contacts 3 are shown in two concentric rows with the contacts staggered with reference to each other. Aconductor 5, carried by arm 4, makes connection between the two sets of contacts 3. The conductor 5 is pressed against the contacts 3 by an adjustable springpressure. (Not shown.) The outer end of arm 4 also carries an insulated spring-pressed conductor 6, which engages the conductors 7 7 fixed to frame 1, and the resistance-contacts 8, which are in connection with the field-circuit of the motor. The arm 4 is pivoted at 9 to frame 1 and has a projecting portion 10, which carries a roller 11. The roller 11 engages cam 12, fixed to the operating-shaft 13. In the position shown the roller is in contact with that part of the cam 12 which is at the greatest distance from the axis of the shaft 13, and consequently the arm 4 is in its upper extreme position. The shape of cam 12 is such, as is apparent from Fig. 1, that rotation of the op crating-shaft in either direction permits the roller 11 to approach nearer the axis of the shaft and allows arm 4 to fall by force of gravity. This arm is retarded in its downward motion by a dash-pot 14, connected thereto. A cook 15 is provided at the top of the dashpot for regulating its action. Upon the operating-shaft is mounted a cylindrical cam 16 for controlling the reversing-switch. The reversing-switch comprises two insulated blades 17 17', which swing about pivot 18. The pivoted support for the blades has fixed thereto apart 19. having its upper edge scalloped and engaged by a spring-pressed plunger 20 within a casing 21, fixed to the frame. Mounted upon the frame are contacts 22, 23. 24, 25, 26, 27, 28, 29,30, and 31, connected as shown in Fig. 5. The blades 17 17 carry, respectively and in electrical connection therewith,the leafcopper contacting-brushes 32 32, which are in constant engagement with the segments 30 31.

Referring to Fig. 5, the parts are represented in the off position, corresponding to that shown in Fig. 1. The positiveline gasses to the lower contact-segment 3 of one set of contacts 3 through resistances to conductor 5 and then through the other contacts 3 and resistances to the lower contact 3 thereof. Connection is made from this contact to the series field-winding 33 of the motor and thence to contacts 26 and 22. The contacts 25 29 are connected to the negative-supply line. (lonnection is made from the contacts 24 28 to the shunt field winding 34 of the motor and thence to the conductor 7. The segment '7 is connected to the contacts 23 27, and the segments 3O 31 are connected to the terminals of the motor-armature There is no position of the reversing-switch at which the shunt field is on open circuit, and I therefore avoid the objectionable effects due to opening the field-circuit. .In the otf position shown the [ield is closed on itself, since the blades 17 17 engage the contacts 23 24: and the contacts 27 28. In this position also the armature is shortcircuited, since there is a closed circuit from segment 30 through 32 17 to contacts 23 24 and 27 28 to blade 17 and brush 32 to segment 31. This is advantageous for the electrical braking effect, tending to bring the motor rapidly to rest. It apparent when the switch is thrown in the direction of the hands of a clock to its extreme position current will pass from positive line through contacts 3 and the two series of starting resistances, then through the series held 33 to contact 22, blade 17, brush 32, segment 30, armature 35, segment 31, brush 32, blade 17, contact 29, to negative line. Current also passes from contact 23 to segment 7, conductor 6, segment 7, through the shunt field to contact 28. \Yhen the switch is now turned toward the ofl position, connection is first broken at contacts 22 and 29. This disconnects the line, and by tracing the circuits it will be seen that the armature is then closed on the shunt field-winding. Upon completing the movement to off position both the shunt field and the armature windings will be closed on themselves, as above explained. hen the switch is thrown from oif position in a direction opposite to the hands of a clock, the circuits established will be similar to those above described, except that the direction of current through the armature will be reversed, thereby reversing the direction of rotation of the motor. Also pivoted upon the bolt 18 is an arm 36, which extends downwardly and carries at its lower end a pin 37. which engages the groove 38 of the cam 16. The arm 36 carries, by means of a pin 39, a leaf-spring 10, which engages the movable part of the reversing-switch on opposite sides of the pivot. The part carrying the pin 39 also carries pins a1, which are also adapted to engage the reversing-switch on opposite sides of its pivot. The form of the cam 16, the development of which is shown in Fig. 4, is such that when the pin 37 engages the middle of the groove 38 the reversing-switch is in the off position shown, and

when the operating-shaft is turned in one direction or the other it causes the pin 37 to travel to the right or left along the operatingshaft. This places tension, by means of one end or the other of the spring 410. upon the reversing-switch. As the tension increases the force of the spring-pressed plunger 20, seated in the central groove on the part '13), is overcome and the switch is suddenly thrown by pressure of spring 40 into engagement with the line-contacts, and the plunger 20 then seats in one of the other grooves. Similarly the switch is suddenly thrown by the spring out of engagement with the line-contacts, thereby reducing the arcing at the corn tacts to a slight amount. If the resistance to movement of the switch is such that one of the pins 11 engages the switclnit will be forced to move by the pin,'and as soon as the switch is freely movable, as when it becomes disengaged from the line-contacts, the spring 10' will rapidly throw the switch. Any slow movement of the switch at the time of breaking circuit connections is consequently prevented. The cam 16 is formed of two identical parts 4&2 L2 and may therefore be made from a single pattern. The two similar parts are illustrated in Fig. 3 and shown displaced axially from each other. Fig. 4: clearly shows in development the two similar parts 42 &2.

In operation the shaft 13 is rotated by a hand-rope from the elevator-car or by any other means desired when the driving-motor is used for other purposes. Since at off position the pin 37 is in the middle of the inclined portion of groove 38, any rotation of the shaft will cause the rapid movement of the pin 37 and the movement of the reversingswitch to its extreme position. The shape of cam 12 is such that the rheostat-arm a will not move until the reversing-switch has been thrown. Upon continuing the movement of the operating-shaft the pin 37 travels in one of the straight portions of groove 38 and tends to produce no further movement of the reversing-switch. The corresponding portion of cam 12, however, is inclined toward the axis of the operating-shaft, and so permits the arm a to fall and cut out the armature resistance. On account of the fact that the two sets of contacts 3 are staggered with reference to each other the resistance-sections will be cut out successively one at a time, giving a gradual increase in speed. \Vhile the arm moves downwardly the conductor 5 will cause the armature resistance to be gradually cut out until it reaches the long segments 3' 3, and during this movement the conductor 5 is passing over the segments 7 7', at which time the lield resistance t3 will be short-circuited thereby. Furthur downward movement of the arm at over the segments or contacts 3 3 will not change the armaturecircuit; but such further movement will cut in sections of the field resistance &3, and con- IEO sequently weaken the field strength to obtain increased speed. Since I provide a single handle for controlling both'the armature resistance and the field resistance, the field resistance is necessarily out in circuit only after the armature resistance is cut out of circuit, and therefore the armature resistance is never inserted or the motor started under a condition of weakened field. The rapidity of the downward movement of arm4 is determined by the dash-pot 14, and no matter how rapidly the operating-shaft is turned the resistance will be slowly cut out, thus insuring the safe starting of the motor. takes place whether the operating-shaft is thrown in one direction from the 011' position or in the reverse direction. The operatingshaft cannot be thrown beyond a certain amount when the pin 37 arrives atone or the other ends of groove 38. This checking movement does away with the necessity of using stops on the controlling-rope of the elevator. hen the operating-shaft is turned so as to stop the motor, the arms will first be positively raised by the cam 12, thus cutting out resistance 43 and cutting in the resistance 2, after which the reversing or main switch will be thrown to the off position, opening the circuit. It is clear that the position of arm 4, and consequently the speed of the motor, may be absolutely controlled and varied by turning the operating-shaft to any desired position. When the switch is in off position, the armature-circuit will be closed, as above explained, and a strong braking effect secured.

In addition to the apparent advantages of simplicity, safe and reliable operation, accessibility of parts, &c., my preferred construction is very compact and may be placed made without departing from the scope and meaning of the claims.

Having thus described my invention, I declare that what I claim as new, and desire to secure by Letters Patent, is'

1. The combination of a rheostathaving a movable arm, a main switch, and means for controlling said rheostat and switch comprising a manually-operated element, a cam device for operatingv said arm, and a cam device for operating said switch, both of said devices being controlled by said element.

2. The combination of a rheostat having a movable arm adapted to fall by gravity'andin such movement to'cut out sections of resistance, means for retarding such downward movement, a main switch, a shaft, a cam there- A similar action.

-on for controlling the position of said arm,

movable arm adapted to fall by gravity and i in such movement to cut out sections of resistance, means for retarding such downward movement, a main switch, a shaft, a plate-cam thereon for controlling the position of said arm, and a cylindrical cam on said shaft for throwing said main switch.

4. The combination of a rheostat having a movable arm adapted to fall by gravity and in such movement to cut out sections of resistance, means for retarding suchdownward movement, a main switch, a shaft, a plate-cam thereon for controlling the position of said arm, and a cylindrical cam on said shaft for throwing said main switch, said cylindrical cam being formed of two similar parts.

5. The combination of a rheostat having a movable arm adapted to fall by; gravity and in such movement to cut out sections of resistance, means for retarding suchdownwardmovement, a main switch, means for giving said switch a quick make-and-break, a shaft, a plate-cam thereon for controlling the position of said arm, and a cylindrical cam on said shaft for throwing said main switch.

6. The combination of a rheostat having a movable arm adapted to fall by gravity and in such movement to cut out sections of resistance, means for retarding such downward movement, a reversing-switch, means for giving said switch a quick make-and-break, a shaft, a plate-cam thereon for controlling the position of said arm, and a cylindrical cam on said shaft for throwing said main switch, said cylindrical cam being formed of two similar parts.

7. The combination of aframe substantially rectangular in outline, a resistance within said frame having contacts on one side of said frame, an arm on the same side of said frame adapted to fall by gravity and in such movement to cut out sections of said resistance,

means for retarding such downward movement, a reversing-switch mounted on an adjacent side of said frame, an operating-shaft on the said latter side, a plate-cam on said shaft for controlling the position of said arm, and acylindrical cam on said shaft for throwing said reversing-switch.

8. The combination of a motor, an armature resistance, afield resistance, an arm controlling both of said resistances, a main switch, and means for controlling said arm and switch comprising a manuallyoperated element, a cam device for operating said arm, and acam device for operating said'switch, both of said devices being controlled by said element.

9. The combination of a motor, an armature resistance, a field resistance, an arm con- IZO controlling the circuits of said motor and for In testimony whereof I affix mysignature in placing the armature and field on closed c1rpresence of two Witnesses. cult When disconnected from the source, a

. HARL E EN manually-operated element, a cam devlce for L s S R 0 operating said arm, and a cam device for 010- WV 1tnesses: erating said circuit-controlling means, both of EDWIN C. GIBBS,

said devices being controlled by said element. CHAS. E. LORD. 

